1.A general use affirmative adjective/response for something that is mind-blowingly awesome, typically somethinng which the lady-folk cannot appreciate. Also used to insult bitches who don't know. See also: Fucking A or Hell yeah
2. The truth/words to live by

1. Guy 1- You wanna play Left 5 Dead?
Guy 2- Bitches don't know.

I was walking down the hall the other day and I overheard two bitchy girls discussing what they didn't know.